Centrifugal countercurrent chromatography has been successful in high efficiency analytical separation with a variety of two-phase solvent systems. For example, see Y. Ito and R. L. Bowman, (1975) Anal. Biochem., 65,310, Y. Ito and R. L. Bowman, U.S. Pat. No. 3,856,669, Dec. 24, 1975, and Y. Ito and R. L. Bowman, U.S. Pat. No. 3,775,309, Nov. 27, 1973. In these systems, two immiscible or partially soluble liquid phases are brought into contact for the transfer of one or more components. In helix countercurrent chromatography a horizontal helical tube is filled with one phase of a two-phase liquid and the other phase is introduced at one end of the helix and passes through to the first phase. In these systems, to enable the countercurrent process to take place inside a very smalldiameter tube having a maximum number of turns, it is desirable to enhance the gravitational field by the use of centrifugation.
However, preparative separation with low interfacial tension phase systems often becomes difficult because of emulsification of the solvent in a large bore column, resulting in carry-over of the stationary phase. See Y. Ito and R. L. Bowman, (1973) J. Chromatogr. Sci., 11, 284. Although droplet countercurrent chromatography developed for preparative purposes can be used, the efficiency of separation achieved on the low interfacial tension n-BuOH (normal butanol) phase system is no more than that of the countercurrent distribution method. See H. Yoshida, C. L. Zimmerman and J. J. Pisano, (1975) Proceedings of the Fourth American Peptide Symposium, 955.